I’m no expert but just helping you kick the tires a little bit - for the audio outs, are you thinking of just running speaker wire from an amp in the server closet to the ceiling of all of the audio out locations?
For what it’s worth, I’ve dabbled with wifi/Bluetooth speakers and while they generally work well, there always seems to be some software update or connectivity dropouts enough that I’d much prefer a wired system to eliminate over-the-air issues for a long-term robust solution.
flash forward to an Android cursing on hands and knees trying to vacuum under the fridge